This invention pertains to grinding machines having structure providing for simultaneous grinding at a plurality of stations for rough and finish grinding, with simultaneous loading and unloading of workpieces at an additional station and with operating mechanism whereby the workpiece is both rotated and moved in an oscillatory path with respect to a grinding element to provide improved finish and flatness for the workpiece, along with improved life of a grinding element, such as a belt.
Multi-station grinding machines of the belt type now used in production conventionally have a table supporting a workpiece with the table movable relative to the grinding element. Such a structure does not perform satisfactorily when there are plural grinding stations, since it is difficult to obtain parallelism between the grinding element and the workpieces at the respective grinding stations.
The Fruth U.S. Pat. No. 2,405,417, discloses a grinding machine wherein an index table carries a series of rotatably mounted work tables and with a grinding element mounted for adjustment relative to the work tables. In this patent, the drive for the rotatable work tables is inter-geared with the drive for the index table, whereby the work tables are not free to continuously rotate in a single direction while an index table oscillates and, in fact, there is no disclosure in this patent of oscillating the index table. Additionally, the structure for adjusting the grinding element does not provide for canting of the grinding element to provide parallelism with the work table.